Because you can't calculate a priori probabilities for a process without specifying mechanism in detail.
How much biology/chemistry/physics are we going through now in middle school/high school? How much global warming/gay gene/gender-myth pop-science crap is being foisted on students now in the name of science.
My kids didn't get a whole lot of that. Your Public School System May Vary.
If we teach that there is a design to life and the universe, and a reason for our existence beyond chance, and truth is real and findable, we will have smarter kids and better scientists.
I disagree completely.
The probabiliites being calculated aren't a priori. Amino acids exist. What are the odds of them forming a protein at random? Dembski wrote a long paper addressing your concern. You can find bits and pieces of it here
More to the point, if the idea that life is designed is a bad one, why is the alternative -- that it occurred by chance -- a good one?